Specific phenomena in carboxylic acids extraction by selected types of hydrophobic ionic liquids (original) (raw)
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Extraction of Carboxylic Acids from Hydrocarbon Mixture Using Imidazolium Ionic Liquids
International Journal of Bioscience, Biochemistry and Bioinformatics, 2012
This study focuses on the extraction performance of selected Imidazolium type ionic liquids on two different carboxylic acids namely benzoic (aromatic) and n-hexanoic (aliphatic) acids from a hydrocarbon bulk liquid. Three types of ionic liquids were used in the liquid-liquid extraction study which comprise of 1-n-butyl-3-methylimidazolium as the cation, coupled with three different anions namely thiocyanate [SCN], octylsulfate [OCS] and trifluoromethanesulfonate [OTF]. The liquid-liquid extraction study was conducted using experimental approach and the finding on its performance is compared against the prediction calculated using molecular simulation approach based on COnductor like Screening MOdel for Real Solvents (COSMO-RS) method. The comparison between the two shows good agreement in the ranking of the extraction performance of the three ionic liquids as well as the trend observed from the experimental results. In addition, the understanding developed from the molecular simulation was found to be useful in explaining the results observed from the experimental work.
Chemical reviews, 2017
Ionic liquids (ILs) have been proposed as promising media for the extraction and separation of bioactive compounds from the most diverse origins. This critical review offers a compilation on the main results achieved by the use of ionic-liquid-based processes in the extraction and separation/purification of a large range of bioactive compounds (including small organic extractable compounds from biomass, lipids, and other hydrophobic compounds, proteins, amino acids, nucleic acids, and pharmaceuticals). ILs have been studied as solvents, cosolvents, cosurfactants, electrolytes, and adjuvants, as well as used in the creation of IL-supported materials for separation purposes. The IL-based processes hitherto reported, such as IL-based solid-liquid extractions, IL-based liquid-liquid extractions, IL-modified materials, and IL-based crystallization approaches, are here reviewed and compared in terms of extraction and separation performance. The key accomplishments and future challenges to...
Journal of Physical Chemistry B, 2009
Extractive fermentation using aqueous biphasic systems (ABS) is a promising separation process since it provides a nondenaturing environment for biomolecules and improves the stability of cells. Due to environmental concerns and toxicity issues related with common volatile organic solvents, ionic liquids (ILs), a new class of nonvolatile alternative solvents, are being currently investigated for extraction purposes. In this work, a wide range of imidazolium-based ILs was studied aiming at obtaining new insights regarding their ability toward the formation of ABS and their capacity to the extraction of biomolecules. On the basis of the IL cations 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium, the IL anion influence on ABS formation was assessed through their combination with chloride, bromide, acetate, hydrogensulfate, methanesulfonate, methylsulfate, ethylsulfate, trifluomethanesulfonate, trifluoroacetate, and dicyanamide. Ternary phase diagrams (and respective tie-lines) formed by these hydrophilic ILs, water, and the inorganic salt K 3 PO 4 , were measured and are reported. The results indicate that the ability of an IL to induce ABS closely follows the decrease in the hydrogen bond accepting strength or the increase in the hydrogen bond acidity of the IL anion. In addition, the extraction capacity of the studied ABS was evaluated through their application to the extraction of an essential amino acid, L-tryptophan. It is shown that the partition coefficients obtained between the IL and the K 3 PO 4 -aqueous rich phases were substantially larger than those typically obtained with polymers-inorganic salts or polymers-polysaccharides aqueous systems.
Hydrophobic Ionic Liquids for Efficient Extraction of Oil from Produced Water
Processes
Produced water contaminated with oil has adverse effects on human health and aquatic life. Providing an efficient method for the removal of oil from produced water is a challenging task. In this study, the effects of carbon chain length and the cation nature of ionic liquids (ILs) on the removal efficiency of oil from produced water were investigated. For this purpose, seven ILs containing the bis (trifluoromethylsulfonyl) imide (NTf2) anion, and various cations such as imidazolium, pyridinium, phosphonium, and ammonium, were employed for the removal of oil from produced water via liquid–liquid extraction. The effects of process parameters such as the initial concentration of oil in produced water, contact time, pH, salinity, phase ratio, and temperature on the removal efficiency of oil were studied and optimized. 1-Decyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ([C10mim][NTf2]) (IL4) was found to give the highest oil extraction efficiency of 92.8% under optimum condit...
Enhanced extraction of antioxidants from aqueous solutions by ionic liquids
Separation and Purification Technology, 2017
In this work, the extraction behavior of the three antioxidants, gallic acid (GA), vanillic acid (VA) and syringic acid (SA) by a series of hydrophobic ionic liquids (ILs) was investigated. The experimental results indicated that the extraction ability of the ILs highly depended on their chemical structures and the hydrophobicity of the three acids. For the ILs with perchlorate (ClO 4 À) as anion, the introduction of hydroxyl group on the cation improved significantly the extraction ability of ILs for GA. For the extraction of VA and SA, the hydrophobic interaction between ILs and VA or SA should also be considered. Thermodynamic analysis confirmed that hydrogen bonding was the main driving force underlying the transfer of the three acids from water to the IL phase. The three acids and ILs could be recovered and recycled, respectively by taking the advantage of pH dependence of the extraction efficiencies. These results suggested the ILs containing perchlorate anion exhibited potential applications in extraction of the three antioxidants from aqueous phase.
The Journal of Physical Chemistry B, 2009
Extractive fermentation using aqueous biphasic systems (ABS) is a promising separation process since it provides a nondenaturing environment for biomolecules and improves the stability of cells. Due to environmental concerns and toxicity issues related with common volatile organic solvents, ionic liquids (ILs), a new class of nonvolatile alternative solvents, are being currently investigated for extraction purposes. In this work, a wide range of imidazolium-based ILs was studied aiming at obtaining new insights regarding their ability toward the formation of ABS and their capacity to the extraction of biomolecules. On the basis of the IL cations 1-ethyl-3-methylimidazolium and 1-butyl-3-methylimidazolium, the IL anion influence on ABS formation was assessed through their combination with chloride, bromide, acetate, hydrogensulfate, methanesulfonate, methylsulfate, ethylsulfate, trifluomethanesulfonate, trifluoroacetate, and dicyanamide. Ternary phase diagrams (and respective tie-lines) formed by these hydrophilic ILs, water, and the inorganic salt K 3 PO 4 , were measured and are reported. The results indicate that the ability of an IL to induce ABS closely follows the decrease in the hydrogen bond accepting strength or the increase in the hydrogen bond acidity of the IL anion. In addition, the extraction capacity of the studied ABS was evaluated through their application to the extraction of an essential amino acid, L-tryptophan. It is shown that the partition coefficients obtained between the IL and the K 3 PO 4 -aqueous rich phases were substantially larger than those typically obtained with polymers-inorganic salts or polymers-polysaccharides aqueous systems.
2012
Growing recognition of the extraordinary physicochemical properties and unique solvation environment afforded by ionic liquids (ILs) has drawn increasing attention to these solvents as media for chemical separations. Until recently, little was known about how ionic liquids behave as solvents in this application, particularly in the extraction of ionic solutes such as metal ions. In contrast to the single pathway observed using molecular diluents (i.e., neutral complex extraction), metal ion extraction in these systems has been shown to proceed through as many as three competing pathways over a wide range of conditions. Despite this added complexity, the favorable physicochemical characteristics of the ionic liquids (e.g., non-flammability and unprecedented structural tunability), along with the higher extraction efficiencies and selectivities sometimes observed with these solvents, suggest that they offer significant potential in various separations applications on both the industrial and analytical scale. This potential will not be fully realized, however, without an improved understanding of the fundamental aspects of metal ion partitioning between ionic liquids and aqueous solutions. The objective of this work, therefore, is to clarify the factors controlling the balance among iii the various partitioning pathways observed when these solvents are employed in extraction. To this end, a series of N,N'-dialkylimidazolium-based ionic liquids have been evaluated as substitutes for the conventional organic solvents (i.e., n-alcohols) frequently employed in the extraction of alkali and alkaline earth cations from acidic aqueous phases by crown ethers. Insight into the fundamental aspects of metal ion extraction in these systems has been obtained by analysis of the acid and extractant dependencies of metal ion distribution ratios, measurements of the IL phase water content and of the solubility of the ionic liquids in the aqueous phase, determination of the partitioning of inorganic ions, and consideration of the relative hydrophobicities of the ionic liquids employed. To assess the potential practical utility of these ionic liquids as extraction solvents, these studies were aimed at obtaining information about the relationship between solvent structure and performance as solvents in the extraction of alkali and alkaline earth metal ions. The results obtained represent an important step in the development of guidelines for the rational design of ionic liquid-based metal ion separation systems.
Ionic liquids as additives to enhance the extraction of antioxidants in aqueous two-phase systems
Separation and Purification Technology, 2014
Aqueous two-phase systems (ATPS) have been proposed as an alternative technique for the extraction, separation and/or purification of diverse biomolecules. Besides the typical polymer-salt ATPS, recently, ionic-liquid-(IL)-salt combinations have been reported to present higher extraction performances than the former systems are able to provide. Therefore, aiming at using the tailoring ability and high extraction efficiencies offered by ILs, yet with lower IL amounts, in this work novel ATPS composed of polyethylene glycol (PEG) and Na 2 SO 4 , using ILs as additives (at 5 or 10 wt%), were studied. Both the determination of the phase diagrams and their extraction efficiencies for gallic, vanillic and syringic acids were determined at 298 K. Furthermore, the effects of the molecular weight of PEG (200, 300, 400 and 600 g mol À1 ) and of the IL chemical structure were investigated. The two-phase formation ability increases with the increase of the PEG molecular weight. Moreover, the addition of low amounts of ILs is favorable for the liquid-liquid demixing. The results obtained indicate that all the antioxidants investigated preferentially partition for the PEG-rich phase although depending on the PEG molecular weight and IL employed. The addition of 5 wt% of IL leads to extraction efficiencies ranging between 80% and 99%. These results clearly demonstrate the ability of the IL to tune the polarity of the PEG-rich phase and where the IL chemical structure plays a dominant role in the extraction of phenolic acids. PEG-salt-IL ATPS represent thus an interesting advance in separation processes and open the door for a new range of IL-based extraction processes.
Ionic liquids as adjuvants for the tailored extraction of biomolecules in aqueous biphasic systems
Green Chemistry, 2010
The potential use of ionic liquids (ILs) as adjuvants in typical polymer-salt aqueous systems for the separation and purification of vital biomolecules is investigated. An innovative study involving the addition of various imidazolium-based ILs to conventional PEG/inorganic salt aqueous biphasic systems (ABS), aiming at controlling their phase behaviour and extraction capability for L-tryptophan, is carried out here. For this purpose, phase diagrams and respective tie-lines for PEG 600/Na 2 SO 4 ABS with the addition of small quantities of IL were established. In addition, the partition coefficients of L-tryptophan were determined in those systems. The results obtained indicate that the addition of small amounts of IL to the typical PEG/inorganic salt aqueous systems could largely control the extraction efficiency for L-tryptophan, and that efficiency depends on the IL employed. Salting-in inducing ILs enhance the partition coefficient of L-tryptophan for the PEG-rich phase while salting-out inducing ILs decrease the partitioning of the amino acid. These results are an interesting advance in biotechnological separation processes regarding the extraction of biomolecules that could be used instead of the common approach of PEG functionalization.
Journal of Separation Science, 2012
Two imidazolium supported ionic liquid phases (SILPs) containing different anions, trifluoromethanesulphonate [CF 3 SO 3 − ], and tetrafluoroborate [BF 4 − ], were synthesized and evaluated as solid-phase extraction sorbents for extracting acidic pharmaceuticals from aqueous samples under strong anion-exchange conditions, which include an effective cleanup of the sample. The best SILP material [MI + ][CF 3 SO 3 − ] was selected and successfully applied to the determination of acidic pharmaceuticals in different types of water samples (river water and effluent wastewater). The results were then compared to the previously synthesized SILP material based on [MI + ][CF 3 COO − ] and the commercially available Oasis MAX sorbent.